Hey Jader,
I put a local PC with lots of hdd space into use as a fog server - there are really good howtos for Ubuntu server + fog.
Then i used the thin client contrib mentioned above by steever to allow my sme (dhcpd server) to onhand pxe requests to the ubuntu server. works well although the deployment of snapins with (fog recommended) installrite via fog is a little headache...
cheers,
shelley